/**
 *  KEYVIEW1.c -- Displays Keyboard and Character Messages
 *              (c) Charles Petzold, 1998
 */

#include <windows.h>
#include "04/sysmets.h"

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT("KeyView1");
    HWND hwnd;
    MSG msg;
    WNDCLASS wndclass;

    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc = WndProc;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = szAppName;

    if (!RegisterClass(&wndclass))
    {
        MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(szAppName,
                        TEXT("Keyboard Message Viewer #1"),
                        WS_OVERLAPPEDWINDOW,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        800,
                        800,
                        NULL,
                        NULL,
                        hInstance,
                        NULL);
    ShowWindow(hwnd, iCmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static int cxClientMax, cyClientMax, cxClient, cyClient, cxChar, cyChar;
    static int cLinesMax, cLines;
    static PMSG pmsg;
    static RECT rectScroll;
    static TCHAR szTop[] =  TEXT("Message    Key Char")
                            TEXT("Repeat Scan Ext ALT Prev Tran");
    static TCHAR szUnd[] =  TEXT("_______    ___ ____")
                            TEXT("______ ____ ___ ___ ____ ____");
    static TCHAR *szFormat[2] = {
        TEXT("%-13s %3d %-15s%c%6u %4d %3s %3s %4s %4s"),
        TEXT("%-13s         0x%04X%1s%c %6u %4d %3s %3s %4s %4s")};
    static TCHAR *szYes = TEXT("YES");
    static TCHAR *szNo = TEXT("No");
    static TCHAR *szDown = TEXT("Down");
    static TCHAR *szUp = TEXT("Up");
    
    static TCHAR * szMessage[] = {
        TEXT("WM_KEYDOWN"),     TEXT("WM_KEYUP"),
        TEXT("WM_CHAR"),        TEXT("WM_DEADCHAR"),
        TEXT("WM_SYSKEYDOWN"),  TEXT("WM_SYSKEYUP"),
        TEXT("WM_SYSCHAR"),     TEXT("WM_SYSDEADCHAR")};
    
    HDC hdc;
    int i, iType;
    PAINTSTRUCT ps;
    TCHAR szBuffer[128], szKeyName[32];
    TEXTMETRIC tm;

    switch (message)
    {
    case WM_CREATE:
    case WM_DISPLAYCHANGE:
            // Get Maximum size of client area
        cxClientMax = GetSystemMetrics(SM_CXMAXIMIZED);
        cyClientMax = GetSystemMetrics(SM_CYMAXIMIZED);
            // Get character size for fixed-pitch font
        hdc = GetDC(hwnd);
        SelectObject(hdc, GetStockObject(SYSTEM_FIXED_FONT));
        GetTextMetrics(hdc, &tm);
        cxChar = tm.tmAveCharWidth;
        cyChar = tm.tmHeight;

        ReleaseDC(hwnd, hdc);

            // Allocate memory for display lines
        if (pmsg) free(pmsg);
        cLinesMax = cyClientMax / cyChar;
        pmsg = malloc(cLinesMax * sizeof(MSG));
        cLines = 0;
            // fall through
        return 0;

    case WM_SIZE:
        if (message == WM_SIZE) {
            cxClient = LOWORD(lParam);
            cyClient = HIWORD(lParam);
        }
            // Calculate scrolling rectangle
        rectScroll.left = 0;
        rectScroll.right = cxClient;
        rectScroll.top = cyChar;
        rectScroll.bottom = cyChar *(cyClient / cyChar);
        InvalidateRect(hwnd, NULL, TRUE);
        return 0;
    case WM_KEYDOWN:
    case WM_KEYUP:
    case WM_CHAR:
    case WM_DEADCHAR:
    case WM_SYSKEYDOWN:
    case WM_SYSKEYUP:
    case WM_SYSCHAR:
    case WM_SYSDEADCHAR:
            // Rearrange storage array
        for (i=cLinesMax-1; i>0; i--) {
            pmsg[i] = pmsg[i-1];
        }
            // Store new message
        pmsg[0].hwnd = hwnd;
        pmsg[0].message = message;
        pmsg[0].wParam = wParam;
        pmsg[0].lParam = lParam;

        cLines = min(cLines+1, cLinesMax);
            // Scroll up the display
        ScrollWindow(hwnd, 0, -cyChar, &rectScroll, &rectScroll);
        break;  // i.e. call DefWindowProc so Sys message work
        
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        SelectObject(hdc, GetStockObject(SYSTEM_FIXED_FONT));
        SetBkMode(hdc, TRANSPARENT);
        TextOut(hdc, 0, 0, szTop, lstrlen(szTop));
        TextOut(hdc, 0, 0, szUnd, lstrlen(szUnd));

        for (i=0; i<min(cLines, cyClient / cyChar-1); i++) {
            iType = pmsg[i].message == WM_CHAR ||
                    pmsg[i].message == WM_SYSCHAR ||
                    pmsg[i].message == WM_DEADCHAR ||
                    pmsg[i].message == WM_SYSDEADCHAR;
            GetKeyNameText(pmsg[i].lParam, szKeyName, sizeof(szKeyName) / sizeof(TCHAR));
            TextOut(hdc, 0, (cyClient / cyChar-1-i) * cyChar, szBuffer, 
                    wsprintf(szBuffer, szFormat[iType], 
                        szMessage[pmsg[i].message - WM_KEYFIRST],
                        pmsg[i].wParam,
                        (PTSTR)(iType ? TEXT("    ") : szKeyName),
                        (TCHAR)(iType ? pmsg[i].wParam : ' '),
                        LOWORD (pmsg[i].lParam),
                        HIWORD (pmsg[i].lParam) & 0xFF,
                        0x01000000 & pmsg[i].lParam ? szYes : szNo,
                        0x20000000 & pmsg[i].lParam ? szYes : szNo,
                        0x40000000 & pmsg[i].lParam ? szDown : szUp,
                        0x80000000 & pmsg[i].lParam ? szUp : szDown)) ;
        }
        EndPaint(hwnd, &ps);
        return 0;

    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}